PRODUCT DESCRIPTION
Product details
MMX Monoblock Crank Hub for BMW N55 and S55
The issues surrounding the original three-piece crankshaft hub on the S55 and N55 engines are, sadly, widely known. Fortunately, these problems are solved with MMR Performance's machined monoblock crankshaft hub.
Our monoblock design ensures that the friction discs will not slip.
The original crankshaft hub's friction material is prone to slipping, which causes a timing alteration that can lead to piston-to-valve contact and, if not addressed within the warranty period, results in an expensive repair bill.
We have developed this monoblock crankshaft hub alongside our optional retaining plate to provide complete peace of mind to owners, both in unmodified factory vehicles and those looking to increase power and torque without worry. MMX Performance has designed the most comprehensive solution on the market at a very competitive price.
Our crankshaft hub is machined from solid heat-treated EN36 steel with a 0.75mm surface hardening, making it incredibly strong and durable. Its single-piece design prevents the friction discs from slipping, and with a new crankshaft bolt (included with the hub) tightened correctly, a substantial improvement in reliability is achieved compared to the original version.
Features
Single-piece design.
Machined from solid heat-treated EN36 steel.
Available with MMX retaining plate.
Complete kit with everything needed.
Additional Information
We also offer a single-piece crankshaft hub with four pins. For Stage 1 tuned S55 and N55 engines, this pinless single-piece MMR crankshaft hub is more than sufficient. Installation is simpler as there is no need to precisely drill the end of the crankshaft to mount the four centering pins. However, for high power/torque engines with tunes beyond this level, we recommend the upgraded pinned crankshaft hub version, which features a 4-pin mounting system for maximum engine safety. The 4-pin version is part number MMR20-1004.
In conjunction with our crankshaft hub, installing the optional MMX retaining plate ensures complete peace of mind for owners and is recommended to be installed at the same time.
The retaining plate eliminates the possibility of the crankshaft bolt loosening due to engine vibrations or resonances. The retaining plate is an additional machined aluminum piece that bolts securely over the head of the crankshaft bolt, making it virtually impossible for it to loosen. The retaining plate part number is MMR20-1002.
Installation Information
BMW S55 & N55 bolt torque: 100 Nm initial torque plus 270 degrees.
Vehicle Compatibility
